Analyzer Calibration - mru SWG100 BIOEX User Manual

Flow meter to
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22.1.

Analyzer calibration

Once in a while it is necessary to recalibrate the analyzer. The exact interval time depends on
the biogas condition (gas concentration, total measuring time) and shall be determined by the
user. MRU recommends at least half yearly calibration.
Calibration is carried out by connecting certified gas cylinder to the analyzer. As those cylinders,
typically are under high pressure (150 to 200 bar) and they contain toxic and/or flammable
gases, make sure that only qualified personal is involved in this calibration procedure. Every
gas cylinder must be equipped with a proper pressure reducing manifold with flow regulating
needle valve.
Applying calibration gas
Depending on the options installed there are two ways of connecting calibration gas:
• Analyzer without calibration gas inlet port:
after zeroing the instrument with clean, free of pollutants ambient air, connect the calibration
gas to the zero gas inlet port. Make sure that between the calibration gas cylinder pressure
reducing manifold and the SWG100 zero gas inlet port, a flow regulating needle valve and a
bypass to ambient air is installed, see sketch at left.
After the calibration procedure, the gas cylinder shall be removed; zero gas inlet port is used
for regular zeroing of the analyzer.
• Analyzer with calibration gas inlet port:
the analyzer equipped with separate calibration inlet port, is internally equipped with a
pressure reducing device which will limit the calibration gas pressure to 50mbar. Therefore
the gas cylinder including a pressure reducing manifold (100 mbar ... 1 bar) may be
permanently connected to this calibration inlet port to perform automatic calibration (user
free settable interval time).
Performing the calibration
• Perform always first a zeroing of the analyzer. Be sure, that the ambient air is clean and free
of pollutants.
During calibration gas supply, please make sure that at all time there is a 5 to 10 l/hr surplus
(bypass) of gas flowing through the flow-meter.
Total consumption of calibration gas is then:
60 l/hr (analyzer) + 10 l/hr (bypass) = 70 l/hr
Generally the calibration time per each gas cylinder is not more than 5 minutes.
• Use the menu
E C
XTRAS
measurement to the values of the calibration gas.
to set the span factor accordingly to align the analyzer's
ALIBRATION
SWG100 BIOGAS User Manual
MRU GmbH, D-74172 Neckarsulm